Reply
 
Thread Tools Display Modes
 
Old 04-17-2017, 11:12 AM   #1
Mini-Skoolie
 
Join Date: Dec 2015
Location: Belfast, NY
Posts: 22
Year: 2004
Coachwork: http://www.skoolie.net/forums/f27/hazys-bus-12678.
Chassis: Freightliner
Engine: Mercedes diesel
Rated Cap: Handicap bus (approx 30)
air pressure in your tires

I have a 2004 thomas on a freightliner chassis 40 capacity or so. Here is my forum of my work on the rig.
http://www.skoolie.net/forums/f27/hazys-bus-12678.html
I am curious what you guys use to determine air pressure. A friend told me that the tires don't have to be at their max (115psi) because the bus isn't running heavy (i weigh 18000 lbs.). Right now I have the tires at 95 psi but was wondering if anyone knows a calculation I could use to figure out what psi they should be at for the weight I am running.

The person told me to go lower to give a more comfortable ride but I don't want to do damage to my brand new tires. Thoughts? What air pressure are you all running in your bus?

I still love my bus. Its awesome!
JJay is offline   Reply With Quote
Old 04-17-2017, 11:16 AM   #2
Bus Crazy
 
brokedown's Avatar
 
Join Date: Dec 2016
Location: St Petersburg, FL
Posts: 2,294
Year: 1997
Coachwork: Bluebird
Chassis: TC2000 FE
Engine: Cummins 5.9
Rated Cap: 72
I always run tires a few psi (~5) below their "max" rating on the side to allow for expansion as they heat up. You don't want to go much below that though, underinflation causes excess heat which is the #1 cause of tire failure. You should check your pressure regularly, and after any significant temperature change.
brokedown is offline   Reply With Quote
Old 04-17-2017, 11:42 AM   #3
Mini-Skoolie
 
Join Date: Dec 2015
Location: Belfast, NY
Posts: 22
Year: 2004
Coachwork: http://www.skoolie.net/forums/f27/hazys-bus-12678.
Chassis: Freightliner
Engine: Mercedes diesel
Rated Cap: Handicap bus (approx 30)
I guess thats my question still though. The tires say max pressure 115psi (5300lbs) which means that at 115psi my busses tires should hold 30,000 lbs or so but since I am only loaded to 18,000 lbs can I go 2/3 that psi/lb rating that is on the tires (to give a little bounce.) Is it proportional? Is their negatives to dropping the psi on the tires since the bus is no longer carrying the weight it once did?

Extra heat build up in the tires should not be an issue as the weight on my bus is much less? I think? I have only had my bus for a year and a half. Last summers trip I ran the tires at 100psi but have dropped them to 90 psi but my fried says I can drop them more but looking for you guys experience. Thats my question.
JJay is offline   Reply With Quote
Old 04-17-2017, 11:48 AM   #4
Bus Crazy
 
turf's Avatar
 
Join Date: Apr 2013
Location: Colorado
Posts: 1,595
Year: 1993
Coachwork: bluebird
Engine: 5.9 Cummins, Allison AT1545
Rated Cap: 2
keep trying and report your findings!

a number of people here run lower tire pressure to soften the ride.

check the tire manufacture's webpage for that tire's info. they probably have what you are looking for.

I've run at 90 and 110. i can't tell any difference, am back at 110 now for sake of mileage (in my head).

good luck
__________________
.
Turfmobile Build Thread
turf is offline   Reply With Quote
Old 04-17-2017, 12:40 PM   #5
Bus Crazy
 
brokedown's Avatar
 
Join Date: Dec 2016
Location: St Petersburg, FL
Posts: 2,294
Year: 1997
Coachwork: Bluebird
Chassis: TC2000 FE
Engine: Cummins 5.9
Rated Cap: 72
What are you trying to accomplish by running a lower tire pressure?
brokedown is offline   Reply With Quote
Old 04-17-2017, 12:43 PM   #6
Mini-Skoolie
 
Join Date: Dec 2015
Location: Belfast, NY
Posts: 22
Year: 2004
Coachwork: http://www.skoolie.net/forums/f27/hazys-bus-12678.
Chassis: Freightliner
Engine: Mercedes diesel
Rated Cap: Handicap bus (approx 30)
I have been told it will "soften" the ride of the bus. I don't see a difference from 110 to 90 but want to know you guys experience.
JJay is offline   Reply With Quote
Old 04-17-2017, 12:46 PM   #7
Bus Geek
 
Robin97396's Avatar
 
Join Date: Feb 2016
Location: Willamina, Oregon
Posts: 6,409
Coachwork: 97 Bluebird TC1000 5.9
Friction increases as you lower your tire pressure, however it can make a difference in your ride quality. In a lighter vehicle I can easily feel the difference from dropping tire pressure. My bus is also 17 or 18 k for weight while empty and there doesn't seem to be any notable difference in ride quality from lowering the tire pressure. I'd rather take good care of my rather expensive tires.
__________________
Robin
Nobody's Business
Robin97396 is offline   Reply With Quote
Old 04-17-2017, 01:58 PM   #8
Bus Geek
 
EastCoastCB's Avatar
 
Join Date: Sep 2014
Location: Eustis FLORIDA
Posts: 18,012
Year: 1999
Coachwork: Thomas
Chassis: Freighliner FS65
Engine: Cat 3126
Rated Cap: 15
Quote:
Originally Posted by brokedown View Post
What are you trying to accomplish by running a lower tire pressure?
It can be used to fine tune the ride and tire life.
If you run at max pressure the middle of the tire will wear too fast.
THere are ways of calculating the proper pressure for heavy truck tires.
My bus doesn't have the same size wheels or tires it left the factory with. The School went from little 19.5's to 22.5's with 10R's. It came from the school with 85 psi in every tire.
I'm still playing around with different pressures myself. It seems to like 95 in front and 90 rear, but I'm still messing with getting it dialed in just right.
__________________
.
Roll Your Own Build Thread
EastCoastCB is offline   Reply With Quote
Old 04-17-2017, 05:35 PM   #9
Bus Crazy
 
Njsurf73's Avatar
 
Join Date: Jan 2017
Location: Massachusetts
Posts: 1,497
Year: 2002
Coachwork: Bluebird
Chassis: Bluebird
Engine: 5.9 Cummins 24v
Rated Cap: 72 pax
Quote:
Originally Posted by EastCoastCB View Post
It can be used to fine tune the ride and tire life.
If you run at max pressure the middle of the tire will wear too fast.
THere are ways of calculating the proper pressure for heavy truck tires.
My bus doesn't have the same size wheels or tires it left the factory with. The School went from little 19.5's to 22.5's with 10R's. It came from the school with 85 psi in every tire.
I'm still playing around with different pressures myself. It seems to like 95 in front and 90 rear, but I'm still messing with getting it dialed in just right.
Just make sure you don't air down enough to allow the rears to touch. That is a recipe for a blowout​.

Sent from my XT1254 using Tapatalk
Njsurf73 is offline   Reply With Quote
Old 04-17-2017, 05:50 PM   #10
Bus Geek
 
Robin97396's Avatar
 
Join Date: Feb 2016
Location: Willamina, Oregon
Posts: 6,409
Coachwork: 97 Bluebird TC1000 5.9
That's right. It creates heat until your tire blows. A rock stuck between the duals will do the same thing.
__________________
Robin
Nobody's Business
Robin97396 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 12:54 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.